Elvish Harbinger 
Creature — Elf Druid
When this creature enters, you may search your library for an Elf card, reveal it, then shuffle and put that card on top.
: Add one mana of any color.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL